Oil-Free Diaphragm Vacuum Pump for Filtration

What is the Oil-Free Diaphragm Vacuum Pump for Filtration?

An oil-free diaphragm vacuum pump for filtration delivers a clean, moderate vacuum for vacuum filtration, aspiration and concentration. With no oil to change and no backstreaming, it is the general-purpose workhorse of liquid handling.

Overview

The oil-free diaphragm pump uses one or two flexing membranes driven by an eccentric shaft, with check valves controlling inlet and outlet. Free-air flow rates are typically 10 to 60 L/min, and ultimate vacuum is around 100 to 8 mbar, enough for filtration, solid-phase extraction and vacuum concentration but not for high-vacuum work. The pump head is made from PTFE, EPDM or fluoropolymer-coated parts to resist solvents and acids, and can often be fitted with a stainless steel or aluminum body. Because there is no oil, there is no oil mist, no backstreaming and no oil change, which simplifies operation in clean laboratories. Some models are chemically resistant versions with entirely PTFE wetted paths. They are quiet, typically below 60 dB(A), and are usually portable with a carrying handle.

How does it work?

A laboratory vacuum pump removes gas from a sealed vessel to lower the pressure. Diaphragm pumps flex a membrane with check valves, drawing gas in and expelling it without oil, which suits filtration, aspiration and general laboratory work. Rotary vane pumps use an eccentric rotor with sliding vanes to trap and compress gas, giving a deeper vacuum for rotary evaporation and drying, but they need oil and protection against solvent vapor. Water aspirators use a Venturi effect in flowing tap water and are inexpensive but consume water and reach only a modest vacuum. In each case the pump is matched to a receiver, trap and gauge, and solvent or acid vapor must be trapped before it reaches the pump. Flow rate, ultimate pressure and chemical compatibility define performance.

What are the key features?

• Oil-free operation with no oil mist or backstreaming
• Free-air flow of 10–60 L/min for filtration and aspiration
• Ultimate vacuum around 100–8 mbar
• PTFE or fluoropolymer-coated wetted parts
• Quiet operation below about 60 dB(A)
• Portable design with carrying handle

What are the technical specifications?

A typical oil-free diaphragm vacuum pump for filtration configuration offers free-air flow rate of 10–60 L/min, ultimate vacuum of 100–8 mbar, number of heads of 1 or 2, wetted material of PTFE or fluoropolymer coated, motor power of 50–180 W and noise level of < 60 dB(A). Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Oil-Free Diaphragm Vacuum Pump for Filtration is used in vacuum filtration, solid-phase extraction, vacuum concentration, aspiration of supernatants and gel drying. Across the wider Vacuum Pumps class, laboratories also deploy it for vacuum filtration and solid-phase extraction, rotary evaporation and solvent recovery and vacuum oven drying and degassing.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61326-1, ISO 21360, EN 12469 and GB 4793.1. Certification candidates for this model are CE, RoHS and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Always fit a liquid trap between the vessel and the pump so that condensate or foam cannot enter the pump head. For solvent work, add a cold trap or an acid-resistant inline filter and change the pump oil regularly, watching for discoloration or emulsion. Vent the exhaust away from the operator when pumping hazardous vapors. Check diaphragms and valves on the maintenance schedule, since they are the usual wear points, and keep spare parts. Mount the pump on a stable surface with adequate ventilation, and confirm the electrical supply and, where required, use a pump rated for the ambient conditions. Follow IEC 61010-1 for electrical safety. Verify the achieved vacuum with a gauge rather than assuming the rated value, and record it for method consistency.

How do I select the right Oil-Free Diaphragm Vacuum Pump for Filtration?

Choose this pump when a moderate vacuum is sufficient and clean, low-maintenance operation is wanted. If you need deeper vacuum for rotary evaporation or ovens, choose a rotary vane pump. In the RFQ, state flow rate, ultimate vacuum, wetted materials and whether a gauge or controller is needed.

How does it compare with other Vacuum Pumps variants?

Choose by the required vacuum level and the vapor being pumped. For filtration, aspiration and vacuum concentration where a moderate vacuum is enough, an oil-free diaphragm pump is usually the right choice, because it needs little maintenance and cannot backstream oil. For rotary evaporation, gel drying and vacuum ovens that need a deeper vacuum, a chemically resistant rotary vane pump with a cold trap and oil mist filter works well. Use a water aspirator only where tap water is available and water use is acceptable. Then match the free-air flow rate to the system volume and the speed of operation you need, and confirm the pump can start against the load. Check wetted materials and diaphragm or vane materials for solvent and acid compatibility, noise level, and whether a gauge, regulator or vacuum controller is included.